Booster pump and suction switch



Jan. 19, 1943. F. "r. FLINT BOOSTER PUMP A ND SUCTION SWITCH Filed March14, 1941 2 Sheets-Sheet l FIG. 1

5%"."1 ELNTOR FORREST T. FLINT W U.

ATTORNEY J 1 4 F. 1'. FLINT 2,308,746

BOOSTER PUMP AND SUCTION SWITCH Filed March 14, 1941 2 Sheets-Sheet 2INVENTOR FORREST T. FLINT WlLR-Q ATTO R N EY Patented Jan. 19, 19432,308,746 BOOSTER PUMP AND SUCTION swrrcn Forrest T. Flint, Florissant,Mo., assignor to Carter Carburetor Corporation, St. Louis, Mo., acorporation of Delaware Application March 14, 1941, Serial 1:10. 383,37114 Claims. (Cl. 123-139) This invention relates to mechanism associatedwith an internal combustion engine for producing a stabilized pressuredifferential and utilizing the same f r controlling the fuel supply andignition syste Many accessories and adjuncts on motor vehicles, such asfuel feed pumps, windshield wipers, oil pumps, and fans may be operatedby the vacuum or pressure differential between the subatmosphericpressure in the intake manifold and the atmosphere. While it has beenfound highly desirable to use such motive power, certain operatingconditions such as rapid acceleration and low speed operation under aheavy load, decrease the pressure difference between the intake maul--fold and the atmosphere to a degree where it is of little or no use as amotive power. This very wide fluctuation of the pressure differentialrenders it undesirable as a motive power for some adjuncts such as avacuum switch constructed to operate within fairly close pressurelimits.

Where an electric fuel pump is used, it is desirably rendered operativeto supply fuel concurrently with energizing of the ignitio system. butsince a driver may neglect to cut off/the igniconnected to the intakemanifold 2 by the fluid tion switch after the engine starts, meansshould be provided to prevent the pumping of fuel at such times.

An object of this invention is to provide a positively driven air pumpfor supplying a pressure differential for operating accessories andadjuncts on a motor vehicle.

Another object of the invention is to provide a positively driven airpump for closing a vacuum operated switch when the engine is beingstarted.

Another object of the invention is to provide a. novel vacuum operatedswitch for controlling electrical system of an internal combustionengine.

Still another object is to provide a fuel pump control switch deviceincluding automatic means to maintain the switch stably closed duringcranking and, at other times, when the engine is operating slowly,while, at the same time, insuring prompt stopping of the pump when theengine stops.

These objects and other more detailed objects hereafter appearing areattained substantially by the device indicated in the accompanyingdrawings in which:

Fig. 1 is a diagrammatical view illustrating an application of theinvention to an internal combustion engine and its associated electricalsys-.

tem.

pressure line 2a. Fluid pressure from the pump for actuating variousaccessories or adjuncts (not shown) is supplied through the pressureline I. A fluid pressure switch 8 actuated by the pump 6 is used forcontrolling the electrical circuits shown in Fig. 1. A generator- 9 isarranged to be driven by the engine in the usual manner and a startingmotor I0 is arranged to, crank the engine. A storage battery is indica dat H. A throttle actuated starting switch may be of any suitableconstruction as the details thereof form no part of the invention.

To energize the starting motor, a lead |3|4 from the battery is providedhaving interposed therein a switch |5 operated by a solenoid IS. Theswitch I5 is normally held open in the position shown by the spring II.The starting motor is grounded at I8, solenoid I6 is grounded at l9,pump motor 4 is grounded at 28, and storage battery II is grounded at20. 1

To energize solenoid l6, there is provided a circuit including batteryll, lead l3, ammeter A, key switch 24, leads 2| and 22, manual starterswitch l2, and lead 23.

A second circuit for operating the fuel pump includes the battery, leadsl3, 2|, and 25, fluid pressure switch 8, and leads 26 and 21. Thiscircult is connected in multiple to the general ignition system asindicated at 29.

The charging circuit includes generator 9, lead 30, reverse currentrelay 33, leads 3|, 32 and 26,

sumcient pressure to cause fluid pressure switch 8 to close, and by thisarrangement the circuit is opened in event the engine ceases operation.6

To better understand the construction and operation oi pressure pump 6and pressure switch 8, reference is made to Figures 2 and 3. The

a pump housing 48 secured to the motor housing 41 by-the bolts v 42 inthe vicinity oi a rotating cam 43 driven, by the motor. A vertical pumpcylinder 44, secured to the top pump 6 comprises of pump housing 49 bybolts 45, is divided into two chambers by a ring sealed piston 46. The

lower chamber formed by piston 46 is in open communication with theinterior of motor housing 4l through the hollow interior of the pumphousing and the opening 41 in the motor housing. In the lower portionof'pump housing 46 so. Openings 53 in the guide member 52 provide ameans for the escape of oil from the well as the guide plunger isreciprocated. A- lever 56, pivoted at 66, has one end 51 bearing on acollar 68 formed on piston rod 6|, while the other end 69 of the leveris held against cam 43 by the upward thrust of spring 68..

Piston 46 is provided with a circularly arranged series of openings 69iorthe passage of fluid downwardly through the piston and a valve disk 6I, backed by a sound deadening material 62, is normally urged againsttheunder surface of piston 46 by a spring 63 to close the openings 68.Surrounding the valve disc, a sound deadening chamber is formed by acircular wall 64 depending from the under side of piston 46 and a bottomplate 66. Wall 64 is provided with small openings66 arranged thereaboutfor distributing and retarding the speed of air passing through thechamber. This chamber also acts as a condensing and collecting chamberfor crank case oil sucked upwardly around piston 46 and drawn backthrough the ports 69., Oil thus collected finds its way through theopenings 66 to the crank case of the engine.

A distributing chamber 61 formed in the cylindercover 66, is providedwith a pair of valve units 69 and 19,respectively, positioned by theentering chamber through line 1 is distributed to the pressure pump orto the intake manifold according to the relativedepressions therein.

An upwardly projecting cup 16 on pump cover 68 has the lower end 01 abellows 16 stretched thereover, the other end of --the bellows beingstretched over a plate 11 thereby forming the ex pansible andcontractiblefluid tight chamber 18. A ring 88 resting on cover 66 withincup 16 has upwardly projecting abutment pin 88a for limiting thedownward movement of plate 11. A compression spring 8| is seated betweenring 88 and plate 1 for extending the bellows. A cover 62 placed overthe bellows is secured to cylinder cover 88 by the bolts 83.

A vertical cylinder 86 in chamber 18 forms one electrical contact of thepressure switch and is insulated from the cylinder cover 68 by thedielectric members 86 and 81. Cylinder 86 is held in place by thebinding post 88 to which is connected electrical conductor 26.Electrical conductor 25 is connected to the binding post 9| which issupported by and .insulated from the cover 82. Binding post 9| has adownwardly extending portion 92 on the end of which is secured.outwardly and upwardly projecting spring contact'flngers 93s1idablycontacting the inner wall of a cup 94 secured to bellows top plate 11.Cup 94 has a depending flnger 94a provided with outwardly and upwardlyprojecting spring contact flngers96 ior slidably contacting cylinder 86when bellows 16 is collapsed. Dielectric washer 99 secured to the end offinger-94 reciprocates in cylinder 86 and member 94. I

Distributing chamber "81 and expansible' strlction v98 retards theinflow of air when the engine ceasesoperation.

The operation of the device-is as follows:

To start the enginejkey switch 24 is closed and upon closing manuallyoperated switch l2,

solenoid .l6 closes the starter circuit thereby causing starting motor19 torcrank the internal combustion engine I. Cranking speed variesfrom9to20 R.P. M.andatthislowspeed2to4 revolutions is suflicient for thepump piston 48 to reduce the air pressure in distributing chamber 61,pressure line 1 and chamber 18 to a point where bellows 16 willpartially collapse and switch contact flngers 96 makes contact with thevertical sidewalls or chamber 86 thereby closing the circuit energizingfuel pump 4 and the general ignition system 29.

The small volume of air in chamber 61, pressure line .1 and chamber 18is exhausted very quickly by the large pressurepump 6 and by the sametoken a leakage of. air inan appreciable amount will cause bellows '16to extend tending to break the contact between the switch contacts,

It is, therefore, necessary that there be a calibrated passageway tochamber 18 from distributing chamber 61 so that the time required forair to fill chamber 18 is greater than the time required for the" upwardstroke of pressure pump 6 during its slowest operation, that is, duringcranking of the engine.

Bellows 16 will pulsate during low speed 'operafrom 4 to 6' seconds theswitch contacts are I broken.

If, for any reason, pump 6 fails to operate and the engine is running,the subatmospheric pressure in the intake manifold 2 will operate the aswitch by way of line 2a. passage 12 and valve unit 18. Valve unit 1,also, may open when high actsas a guide for suction exists in the engineintake and pump 6 is operating slowly, as during idling.

In the event that pump piston 46 or its seal is broken and the enginecontinues operation, intake suction maintains the fuel pump and ignitionin operation, except under the most adverse suction conditions, butvalve unit 69 remains closed and suction in the intake manifold cannotremove the oil vapor from the crankcase.

The detailed drawings and description are intended to be illustrative,not limiting, and the use of all modifications within the scope of theappended claims is contemplated.

I claim:

1. In an electrical circuit control for an internal combustion engine, apressure chamber having a resiliently movable wall, an electrical switchconstructed and arranged to be actuated by said movable wall, areciprocating fluid pressure pump actuated by said engine, and arestricted passageway from said pressure chamber to said pressure pumpfor retarding the movement of said wall.

2. In a device for controlling an electrical circuit of an internalcombustion engine comprising a suction pump actuated by said engine, afluid chamber having a, movable wall, an electrical switch constructedand arranged to be actuated by said movable wall, a passageway from saidpump to said chamber and an atmospheric vent to said passageway.

3. In a device for controlling an electrical circuit of an internalcombustion engine, a suction pump actuated by said engine, a fluidchamber having a movable wall, a passageway connecting said pump andsaid chamber, an electrical switch constructed and arranged to beactuated by the movement of said wall, and an atmospheric vent for saidchamber.

4. In a device of the class described having a suction pump actuated byan internal combustion engine, a fluid distributing chamber interposedbetween fluid actuated devices and said pump, a fluid connection betweensaid chamber and the intake manifold of said engine, and a valve in saidfluid connection, said pump being constructed and arranged to developsuction sufflcient to hold said valve closed throughout most of thenormal operating range of said engine.

5. In a device of the class described having a electrical fuel pump forsupplying fuel to said engine, an electrical circuit for energizing saidfuel pump, a fluid chamber in communication with said pump, said chamberhaving a wall movable in one direction by said pump, a switch interposedin said circuit and actuated by said wall, and means for moving saidwall in the opposite direction for interrupting said circuit when saidengine ceases to operate.

'7. In combination, an internal combustion engine having an ignitionsystem, a suction pump, an electric fuel pump, an electrical circuit forsaid pump, and means for breaking said electrical circuit when thesuction in the pump falls below a predetermined point.

8. In combination, an internal combustion engine having an ignitionsystem, a suction pump, an electricfuel pump, an incomplete electricalcircuit for said fuel pump, and means for completing said circuit whensuction in said pump reaches a predetermined point.

9. In combination, an internal combustion engine having an ignitionsystem, a suction pump actuated by said engine, and means for openingsaid ignition system when the suction in said pump falls belowa.predetermined point for a period of time.

10. In combination, an internal combustion engine having an ignitionsystem, a suction pump actuated by said engine, an electric fuel pump,and means for energizing said fuel pump and ignition system when suctionin said pump reaches a predetermined point.

11. In combination, an internal combustion engine having an ignitionsystem, a suction pump actuated by said engine, an electric fuel pump,an electrical circuit for said fuel pump and said ignition system, andmeans for breaking said circuit when the suction in said pump fallsbelow a predetermined point.

12. A control device for an internal combustion engine comprising achamber having a movable wall, an actuating connection between said walland the control, an engine operated pump having a fluid connection tosaid chamber for actuating said wall in one direction, means yieldinglyurging said wall in the opposite direction, a restricted atmosphericport in a wall of said passage to relieve pressure differential in saidchamber, and a restriction in said fluid connection to retard theresponse of said movable wall to variations in pump pressure.

13. A control as specified in claim 12 in which said atmospheric port isbetween said pump and the restriction in said fluid connection.

14. A control as specified in claim 12 in which said pump includes areciprocating pumping member, said restriction retarding recovery ofsaid chamber during the return stroke of said member under low speedpumping conditions.

FORREST T. FLINT.

